The C60 grafted poly(N-vinyl carbazole) (PVK) polymer(CGP) was prepared by simple radical polymerization initiated by BPO at 90℃.The products were characterized by UV-Vis, FTIR, GPC and fluorescence and it was proven...The C60 grafted poly(N-vinyl carbazole) (PVK) polymer(CGP) was prepared by simple radical polymerization initiated by BPO at 90℃.The products were characterized by UV-Vis, FTIR, GPC and fluorescence and it was proven that C60 was grafted covalently to the PVK. The C60 moiety in the product was about 1. 2% (mass fraction). The photoconductlvity study revealed that the photoconductivity of PVK was improved obviously through grafting C60.The half time of light decaying (t1/2) of CGP reached 0. 35 s.展开更多
A vinyl monomer having an electron-donating moiety, p-(N,N-dimethylamino)styrenc (DMAS),was synthesized. It was combined with benzoyl peroxide (BPO) to form a redox initiation system to initiatethe polymerization of m...A vinyl monomer having an electron-donating moiety, p-(N,N-dimethylamino)styrenc (DMAS),was synthesized. It was combined with benzoyl peroxide (BPO) to form a redox initiation system to initiatethe polymerization of methyl methacrylate (MMA). UV spectra measurements show that DMAS enters thePMMA chain as well. Both DMAS and its polymer P(DMAS) display strong fluorescence, and thefluorescence can be quenched by electron-deficient compounds such as methacrylonitrile, fumaronitrile andmethyl methacrylate etc. Moreover, DMAS can also form charge transfer complex (CTC) with strongelectron acceptors such as tetracyanoethylene (TCNE). The difference between the photochemical propertiesof DMAS and P(DMAS) were explained in terms of molecular structure change and polymer conformationeffect in solution. In addition, the CTC and exciplex formation of DMAS or P(DMAS) with C_(60) were alsostudied.展开更多
Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au...Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C60Py molecules on Au (111) only exhibited randoml aggregation of C60Py even the films were annealed at 50 and 105℃. By co-assembling with benzyl mercaptan (BM), the C60Py- BM films showed highly dense aggregation, but C60Py assemblies still had disordered structure. After the co-assembled C60Py-BM films were annealed at 50℃, BM molecules were partially desorbed, but the assembly of C60Py remained without obvious change. After the co-assembled C60Py-BM films were further annealed at 105℃, the C60Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C60Py monolayer.展开更多
Structural stability and Si-substitution pattern in fullerene cage of C_(60−n)Sin are thoroughly investigated by integrating density functional calculations with a colorbond graph(CBG)model.We find that the parameteri...Structural stability and Si-substitution pattern in fullerene cage of C_(60−n)Sin are thoroughly investigated by integrating density functional calculations with a colorbond graph(CBG)model.We find that the parameterized CBG model with genetic algorithms can efficiently scan the large configuration space of alloy and therefore identify the low-energy region within the first-principles accuracy.Low-energy(stable)structures of C_(60−n)Sin in carbon-rich region(1≤n≤30)were identified and the silicon atoms are found to tend to aggregate in the fullerene cage.The mixing energy of these low-energy structures is ~35 meV/atom and insensitive to the Si concentration.We expect that these alloy fullerene cages can be synthesized experimentally at elevated temperatures.展开更多
文摘The C60 grafted poly(N-vinyl carbazole) (PVK) polymer(CGP) was prepared by simple radical polymerization initiated by BPO at 90℃.The products were characterized by UV-Vis, FTIR, GPC and fluorescence and it was proven that C60 was grafted covalently to the PVK. The C60 moiety in the product was about 1. 2% (mass fraction). The photoconductlvity study revealed that the photoconductivity of PVK was improved obviously through grafting C60.The half time of light decaying (t1/2) of CGP reached 0. 35 s.
基金This project was supported by the National Natural Science Foundation of China.
文摘A vinyl monomer having an electron-donating moiety, p-(N,N-dimethylamino)styrenc (DMAS),was synthesized. It was combined with benzoyl peroxide (BPO) to form a redox initiation system to initiatethe polymerization of methyl methacrylate (MMA). UV spectra measurements show that DMAS enters thePMMA chain as well. Both DMAS and its polymer P(DMAS) display strong fluorescence, and thefluorescence can be quenched by electron-deficient compounds such as methacrylonitrile, fumaronitrile andmethyl methacrylate etc. Moreover, DMAS can also form charge transfer complex (CTC) with strongelectron acceptors such as tetracyanoethylene (TCNE). The difference between the photochemical propertiesof DMAS and P(DMAS) were explained in terms of molecular structure change and polymer conformationeffect in solution. In addition, the CTC and exciplex formation of DMAS or P(DMAS) with C_(60) were alsostudied.
基金supported by the National Project for the Development of Key Fundamental Science in China(G2001CB3095)the National Natural Science Foundation of China(Grant Nos.50121202,50132030&10374083).
文摘Self-assembled monolayers of novel C60 derivative, N-3-γ-pyridyl Aza[60]fulleroid (C60Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C60Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C60Py molecules on Au (111) only exhibited randoml aggregation of C60Py even the films were annealed at 50 and 105℃. By co-assembling with benzyl mercaptan (BM), the C60Py- BM films showed highly dense aggregation, but C60Py assemblies still had disordered structure. After the co-assembled C60Py-BM films were annealed at 50℃, BM molecules were partially desorbed, but the assembly of C60Py remained without obvious change. After the co-assembled C60Py-BM films were further annealed at 105℃, the C60Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C60Py monolayer.
基金supported from Academia Sinica and Nanyang Technological University.
文摘Structural stability and Si-substitution pattern in fullerene cage of C_(60−n)Sin are thoroughly investigated by integrating density functional calculations with a colorbond graph(CBG)model.We find that the parameterized CBG model with genetic algorithms can efficiently scan the large configuration space of alloy and therefore identify the low-energy region within the first-principles accuracy.Low-energy(stable)structures of C_(60−n)Sin in carbon-rich region(1≤n≤30)were identified and the silicon atoms are found to tend to aggregate in the fullerene cage.The mixing energy of these low-energy structures is ~35 meV/atom and insensitive to the Si concentration.We expect that these alloy fullerene cages can be synthesized experimentally at elevated temperatures.
